Sorry, you need to enable JavaScript to visit this website.

office.cense@iisc.ac.in | +91-80-2293 3276/ +91-80-2293 3291 | Sitemap

Electrolithography

Electrolithography is a new patterning technique developed at CeNSE based on electric field induced material transport. This technique can be used for drawing patterns having dimensions from a few nanometres to a few hundred micrometres at ambient conditions. The uniqueness of this  technique is  to  create etch patterns  using  electric  biased  scanning  tip as  against  the conventional  patterning  techniques based  on  deep-UV or electron  beam  irradiation. In the particular case of Cr thin film deposited on an insulating substrate, application of high electric-field between two point electrodes results in liquefaction and subsequent flow of the liquefied material. Electrolithography uses this phenomenon for writing patterns, as described  below.

Figure 1:Process flow of the standard electrolithography technique: The process starts with a substrate spin-coated with a polymer followed by the deposition of a top layer of Cr thin film. (1) In the first step, the top Cr layer is etched in the desired pattern using electromigration. (2) Next, the polymer is etched in the patterned region by dipping it in an appropriate solvent. The inset shows the zoomed view of the trench made in the polymer. (3) Subsequently, the desired material is deposited, and (4) lift-off is used to transfer the final pattern on the desired material

Figure 2:  Various patterns created using electrolithography : 3-D AFM images of the narrowest trench in PMMA with a channel width of 9 nm and narrowest Ti thin film line with an average width  of  40  nm  and  thickness  30  nm.  Bottom  SEM  images  are  of  various  types  of  patterns fabricated in Au (75 nm thick) on Si substrate.

Considering  the  complexity  and  the  cost  of  the  lithography  processes,  this  technique  is  far better than the e-beam lithography or UV based photolithography, which require high energy e-beam or UV sources, ultra-high vacuum and very expensive instrumentation to reach nano-scale resolutions. To read more about the process please look into http://www.nature.com/articles/srep17753

Patent:

A device, system and method generating structures on a substrate by electromigration, Santanu Talukder, Praveen Kumar, and RudraPratap, Indian patent application -IPA12130001 (filed on 9th December, 2014).

Subscribe to RSS - Electrolithography